Graphene in Liquid-Phase Electron Microscopy
Graphene liquid cells are nano to microscale pockets of water sealed in two layers of graphene. Around the pocket, the two graphene layers stick together due to strong static forces giving rise to a very stable pocket that is both water and vacuum tight. Graphene liquid cells form an ideal platform to study samples in liquid in transmission electron microscopy, where the ultra-thin graphene functions as the most electron transparent window currently available. Typical GLCs have a thickness ranging from a tens to hundreds of nanometers, making them ideally transparent to the electron beam. Graphene is highly conductive and a demonstrated radical scavenger. When used as substrate in TEM imaging, it protects the sample against electron beam damage caused by radiolysis, charging or heating.
Samples in graphene liquid cells are dissolved and hydrated, retaining in many aspects their native state. With graphene liquid cells, drying, freezing or fixating are no longer required. The resulting ultra-thin GLC structures lead to high resolution imaging of biological and organic matter without the need for staining. The room-temperature assembly processes drastically simplify the sample preparation compared to cryo-EM methods. Application areas include the direct sub-nanometer resolution imaging of proteins, nanomaterials and in particular metallic nanoparticles at atomic resolution.
- Low e-dose imaging
- Stained / unstained samples
- Buffer-filled GLCs
- Dynamic imaging
- Proteins & protein complexes
- DNA, RNA
- Whole living cell processes
Graphene liquid cells offer a drastically thinner structure then conventional SiN-based liquid cells. New levels of detail are resolved with greater ease than ever before.
- Dynamic processes, formation, aggregation, degradation of
- Electrode materials
- Core-shell particles
- Low e-dose imaging
- Atomic resolution
Vitrotem’s patented spacer technology grants straightforward control over the thickness of the liquid layer in the liquid cells. The optimal liquid cell thickness depends on the dimensions of the sample under study: liquid cells should accommodate the sample without inducing deformation while also offering the thinnest possible structure to minimize obstruction of the transmission electron beam. In this way, optimal resolution in TEM imaging can be achieved.
The use of Vitrotem spacer technology drastically boosts the density of liquid cells on the grid and the volume of induvial liquid cells. Whereas early studies into graphene liquid cells reported low density and poor reproducibility, with the introduction of spacers technology, graphene liquid cell-based TEM becomes a reliable systematic analysis tool.